Recently, wind turbines have received increased attention as an environmentally safe and relatively inexpensive alternative energy source. With this growing interest, considerable efforts have been made to develop wind turbines that are reliable and efficient.
Generally, a wind turbine includes a rotor having a rotatable hub assembly having multiple rotor blades. The rotor is mounted within a housing or nacelle, which is positioned on top of a truss or tubular tower. Utility grade wind turbines (i.e., wind turbines designed to provide electrical power to a utility grid) can have large rotors (e.g., 30 or more meters in diameter). Blades on these rotors transform wind energy into a rotational torque or force that drives one or more generators. The generators may be rotationally coupled to the rotor through a gearbox. The gearbox steps up the inherently low rotational speed of the turbine rotor for the generator to efficiently convert mechanical energy to electrical energy, which is fed into a utility grid.
Gearless direct drive wind turbines also exist. The rotor, generator, gearbox and other components are typically mounted within a housing, or nacelle, that is positioned on top of a tower.
Wind turbine components, such as bearings, gears, and/or rotor blades may become worn down or damaged over time. To detect such component damage, wind turbines often include a monitoring system that measures vibrations generated by the component during an operation of the wind turbine. Such monitoring systems may be complex and/or may require significant computational resources to extract component damage information from the measured vibrations.
Operational detriments may eventually cause suboptimal performance, whether temporarily (e.g., rotor blade icing) or indefinitely (e.g., structural damage to a rotor blade). At least some known methods of monitoring wind turbines detect operational detriments indirectly by detecting anomalies or symptoms, such as decreased power output and/or inoperability, of a wind turbine. Moreover, because many potential causes exist for such anomalies or symptoms, determining the root cause of an anomaly or symptom requires manual inspection by a service technician, introducing undesirable delay and expense before the root cause can be addressed. In view of the disadvantages associated with the current solutions, there is a need in the art for improved methods and systems for monitoring wind turbines.